APA (7th ed.) Citation

United States. Bureau of Mines. (1939). Washability studies of America and Pratt coal beds at Gorgas, Ala. [s.n.].

Chicago Style (17th ed.) Citation

United States. Bureau of Mines. Washability Studies of America and Pratt Coal Beds at Gorgas, Ala. [Washington]: [s.n.], 1939.

MLA (9th ed.) Citation

United States. Bureau of Mines. Washability Studies of America and Pratt Coal Beds at Gorgas, Ala. [s.n.], 1939.

Warning: These citations may not always be 100% accurate.